PCK9447BD,157 NXP Semiconductors, PCK9447BD,157 Datasheet - Page 10

• Manufacturer Part Number: PCK9447BD,157
• Description: IC FANOUT BUFFER 1:9 32LQFP
• Manufacturer: NXP Semiconductors
• Type: Fanout Buffer (Distribution), Multiplexerr

Specifications of PCK9447BD,157

• Number Of Circuits: 1
• Ratio - Input:output: 2:9
• Differential - Input:output: No/No
• Input: LVCMOS
• Output: LVCMOS
• Frequency - Max: 350MHz
• Voltage - Supply: 2.375 V ~ 3.465 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-LQFP
• Frequency-max: 350MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 568-3565; 935280283157; PCK9447BD

Philips Semiconductors
9397 750 12522
Product data sheet
At the load end the voltage will double, due to the near unity reflection coefficient, to 2.5 V.
It will then increment towards the quiescent 3.0 V in steps separated by one round trip
delay (in this case 4.0 ns).
Since this step is well above the threshold region it will not cause any false clock
triggering, however designers may be uncomfortable with unwanted reflections on the
line. To better match the impedances when driving multiple lines, the situation in
should be used. In this case the series terminating resistors are reduced such that when
the parallel combination is added to the output buffer impedance the line impedance is
perfectly matched.
Z
V
R
R
Fig 12. Single versus dual line termination waveforms
Fig 13. Optimized dual line termination
O
S
O
L
=
=
=
=
33
17
3.0
50
17
25
---------------------------------- -
16.5
33
50
+
=
+
16
25
25
17
+
voltage
25
16
(V)
Rev. 01 — 13 October 2005
3.0
2.0
1.0
0.5
IN
0
=
0
=
1.28 V
50
PCK9447
OUTPUT
IN
BUFFER
4
50
17
3.3 V/2.5 V 1 : 9 LVCMOS clock fan-out buffer
OutA
t
OutB
t
d
d
R S = 16
R S = 16
8
= 3.8956 ns
= 3.9386 ns
12
Z o = 50
Z o = 50
Z o = 50
time (ns)
002aaa679
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
002aaa719
14
PCK9447
Figure 13
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